US officials will pick up discussions with their British, French and German counterparts on Thursday over the fate of the Iran nuclear deal, weeks ahead of a deadline set by US President Donald Trump threatening to pull out of the accord.

Trump administration officials say the talks are at an “advanced” stage entering their latest round of meetings in Berlin. The president wants European allies to join him in demanding an end to Iran’s ballistic-missile testing, which are not addressed by the nuclear deal; unrestricted access for UN nuclear inspectors to Iran’s military sites, which have previously hosted nuclear weapons experimentation; and permanent caps on Iran’s enrichment of fissile material, which in the current deal sunset within 10 to 15 years.

Israeli officials said that they believe Trump is serious in his threat to withdraw from the deal by mid- May unless these three European governments – the “E3” – demonstrate their willingness to renegotiate on these points. The US-E3 talks dominated Trump’s conversation with Prime Minister Benjamin Netanyahu at the White House last week.

So far, European powers have expressed a willingness to discuss all of Trump’s concerns but adamantly believe, nonetheless, that the 2015 nuclear deal, formally known as the Joint Comprehensive Plan of Action, should remain in its current form.

Trump has said that he will allow for the reimposition of nuclear-related sanctions on Iran upon a mid-May waiver deadline unless Europe agrees to some form of renegotiation. White House officials say they want to negotiate on new terms with the E3 and not with Iran itself.